Re: thousands of threads & kernel continuations

Andrew P. Mullhaupt (
Mon, 28 Apr 1997 20:34:32 -0400

Floody wrote on 4/28/97 1:29 pm:

> You can only have one
>process per processor, so
>what's the point of
>multi-processing (beyond
>the number of physical
>processors you have).

The point is that you may have some of the processes in a state where they
cannot run at a given instant. What makes the most sense is an intelligent
combination of queues for some sorts of waiting processes and blocked
threads for others. What is intelligent? Queues make sense when processes
will behave according to a good queue discipline, (they will not
asynchronously defect too often, etc.) But when the blocked process may do
all sorts of different things before the thing it is ostensibly blocked
for, queueing may be a loss.

Note that a not good enough queue can easily become a loss just by slowing
down to the point where nobody wants to wait long enough to get served.